1.\"- 2.\" Copyright (c) 2012 Bjoern A. Zeeb <bz@FreeBSD.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd December 28, 2012 29.Dt WBWD 4 30.Os 31.Sh NAME 32.Nm wbwd 33.Nd device driver for watchdog timer found on Winbond Super I/O chips 34.Sh SYNOPSIS 35To compile this driver into the kernel, place the following line in your 36kernel configuration file: 37.Bd -ragged -offset indent 38.Cd "device wbwd" 39.Ed 40.Pp 41Alternatively, to load the driver as a module at boot time, place the following 42line in 43.Xr loader.conf 5 : 44.Bd -literal -offset indent 45wbwd_load="YES" 46.Ed 47.Sh DESCRIPTION 48The 49.Nm 50driver provides 51.Xr watchdog 4 52support for the watchdog interrupt timer present on at least the following 53Winbond Super I/O chips: 54.Pp 55.Bl -bullet -compact 56.It 5783627HF/F/HG/G Rev. G 58.It 5983627HF/F/HG/G Rev. J 60.It 6183627HF/F/HG/G Rev. UD-A 62.It 6383627DHG IC ver. 5 64.El 65.Sh SYSCTL VARIABLES 66The 67.Nm 68driver provides the following options as 69.Xr sysctl 8 70variables. 71.Bl -tag -width "xxxxxx" 72.It Va dev.wbwd.0.timeout_override 73This variable allows to program the timer to a value independent on the one 74provided by the 75.Xr watchdog 4 76framework while still relying on the regular updates from e.g. 77.Xr watchdogd 8 . 78This is particularly useful if your system provides multiple watchdogs and 79you want them to fire in a special sequence to trigger an NMI after a shorter 80period than the reset timeout for example. 81The value set must not be lower than the sleep time of 82.Xr watchdogd 8 . 83A value of 0 disables this feature and the timeout value provided by 84.Xr watchdog 4 85will be used. 86.It Va dev.wbwd.0.debug_verbose 87If set this sysctl will tell the driver to log its current state before and 88after the timer reset on each invocation from 89.Xr watchdog 9 90to the kernel message buffer for debugging. 91.It Va dev.wbwd.0.debug 92This read-only value gives the state of some registers on last update. 93.El 94.Pp 95The 96.Nm 97driver also provides further sysctl options that are hidden by default. 98See the source code for more information. 99.Sh SEE ALSO 100.Xr watchdog 4 , 101.Xr device.hints 5 , 102.Xr watchdog 8 , 103.Xr watchdogd 8 , 104.Xr watchdog 9 105.Sh HISTORY 106The 107.Nm 108driver first appeared in 109.Fx 10.0 . 110.Sh AUTHORS 111.An -nosplit 112This manual page was written by 113.An Bjoern A. Zeeb Aq bz@FreeBSD.org . 114